Siemens HGB2K125B Molded Case Circuit Breaker
- 125A
- 2 Pole
- Bolt-On
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Siemens HGB2K125B - 125A 2 Pole Molded Case Circuit Breaker
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Description
Built to protect circuits against overloads and short circuits, the Siemens HGB2K125B is a molded case circuit breaker rated 125A with 2 poles. It belongs to the HGB series and has a load side lug terminal connection. Thermal magnetic tripping combines thermal overload response with magnetic short-circuit response. Its LI trip function provides long-time and instantaneous protection.Specifications
| Brand | Siemens |
|---|---|
| Part Number | HGB2K125B |
| Series | HGB |
| Amperage | 125A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC, 480VAC, 600Y/347VAC, 125/250VDC |
| Phase | 1 |
| AIC Rating | 100kA @ 240VAC, 35kA @ 480VAC, 14kA @ 600Y/347VAC, 14kA @ 125/250VDC |
| Frame Type | HGB |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1, P2, P3, P4, P5 Panelboards |
| Wire Gauge | 8-1/0 AWG |
| Max Wire | 1/0 AWG |
| Min Wire | 8 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Fixed Magnetic |
| Available Options | Alarm Switch, Auxiliary Switch, Shunt Trip |
|---|---|
| Accessories | Load Side Lugs |
| Standards | CSA C22.2 No. 5, IEC 60947-2, NEMA AB 1, UL 489 |
| Approval | CSA, NOM, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, High Interrupting Capacity, Reverse Feed |
Product FAQs
7 answersHow should I use the Siemens HGB2K125B's 125A rating when selecting circuit protection?
The 125A rating is the breaker's rated current. Coordinate it with the calculated load and conductor ampacity rather than treating it as the current at which the breaker trips instantly.
Which system voltages can this breaker be selected for?
Its voltage ratings are 240VAC, 480VAC, 600Y/347VAC, and 125/250VDC. Match both the system voltage and AC or DC operation to the applicable rating. The 600Y/347VAC rating applies to a wye system.
How do I check the interrupting rating against available fault current?
Compare available fault current at the installation point with the interrupting rating at the applicable voltage: 35kAIC at 480V or 14kAIC at 600Y/347VAC. Select protection with an interrupting rating at least equal to the available fault current.
What does the thermal-magnetic LI trip do?
The LI function combines long-time overload protection with instantaneous short-circuit protection. The thermal element responds to sustained overloads, while the magnetic element responds rapidly to high short-circuit current.
Can I adjust the thermal or magnetic trip settings?
Both the thermal and magnetic trip settings are fixed. Select this breaker where fixed trip characteristics meet the circuit's protection requirements, rather than where field-adjustable settings are needed.
What conductor sizes can I terminate on the load side?
The load-side lug accepts conductors in the 8-1/0 AWG range. Keep the selected conductor size within that range and coordinate conductor ampacity with the circuit load and breaker rating.
How does the pole configuration guide circuit selection?
This is a 2-pole, single-phase breaker. Select it for a single-phase circuit requiring two protected conductor paths.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 2 reviews.
- CSCody S.Verified BuyerReviewingSiemens HGB3B020B - 20A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars12/1/25I love SuperBreakers
Excellent shipping time and everything works perfectly
- JMJessica M.ReviewingSiemens HGB3B020B - 20A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars8/16/23works as intended
works as intended